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From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, gospo@redhat.com, bphilips@novell.com,
	Andi Kleen <ak@linux.intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, Alexander Duyck <alexander.h.duyck@intel.com>,
	Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Subject: [net-next-2.6 PATCH] x86: Drop CONFIG_MCORE2 check around setting of NET_IP_ALIGN
Date: Thu, 01 Jul 2010 16:28:27 -0700	[thread overview]
Message-ID: <20100701232742.15934.49030.stgit@localhost.localdomain> (raw)

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch removes the CONFIG_MCORE2 check from around NET_IP_ALIGN.  It is
based on a suggestion from Andi Kleen.  The assumption is that there are
not any x86 cores where unaligned access is really slow, and this change
would allow for a performance improvement to still exist on configurations
that are not necessarily optimized for Core 2.

Cc: Andi Kleen <ak@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---

 arch/x86/include/asm/system.h |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h
index b4293fc..1db9bd2 100644
--- a/arch/x86/include/asm/system.h
+++ b/arch/x86/include/asm/system.h
@@ -457,7 +457,6 @@ static inline void rdtsc_barrier(void)
 	alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
 }
 
-#ifdef CONFIG_MCORE2
 /*
  * We handle most unaligned accesses in hardware.  On the other hand
  * unaligned DMA can be quite expensive on some Nehalem processors.
@@ -465,5 +464,4 @@ static inline void rdtsc_barrier(void)
  * Based on this we disable the IP header alignment in network drivers.
  */
 #define NET_IP_ALIGN	0
-#endif
 #endif /* _ASM_X86_SYSTEM_H */


             reply	other threads:[~2010-07-01 23:28 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-01 23:28 Jeff Kirsher [this message]
2010-07-02  0:26 ` [net-next-2.6 PATCH] x86: Drop CONFIG_MCORE2 check around setting of NET_IP_ALIGN Stephen Hemminger
2010-07-02  1:15 ` H. Peter Anvin
2010-07-02  5:49 ` David Miller

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